Aromatic amines and fuels containing the same



Patented Feb. 15, 1949 AROMATIC AMINES AND FUELS CONTAINING THE SAME John W. Orelup, Short Hills, N. J.

No Drawing. Application April 15, 1944, Serial N0. 531,289

7 Claims.

Many of the high octane motor fuels now in use comprise petroleum distillates containing substantial quantities of aromatic amines such as xylidines, toluodines, anilines, etc., as an antiknock agent. These amines when freshly distilled and in a pure state are water white or of a very light color, although sometimes during the process of distillation they may become more or less colored. Also they rapidly become discolored from standing, heating or exposure to light. The darkening of the color of these products indicates deterioration thereof, possibly in such a way as to affect their elficiency, by raising the gum content of the fuels containing them. The discoloration also interferes with the effective use of marking colors, such as colors employed to indicate the grades of the fuel. It is therefore highly desirable to produce fuels in which the aromatic amines are colorless or light in color when the distillate is first prepared, and to render the fuels resistant to color deterioration during storage or when exposed to heat or light. It is also desirable to improve and preserve the color of aromatic amines of the character indicated for various uses to which those amines may be put other than in the preparation of motor fuel.

Various processes for the prevention of darkening of amines have been tried, many of which include treating the amine with an inhibitor of some kind. Previously suggested have been sodium sulphide, oxalic acid, zinc or iron, mphenylene diamine, pretreatments with Irish peat, acetone, or maleic anhydride. Such processes, however, have not been wholly successful and the object of the present invention is to provide a more effective means and method for improving the color and permanency of color of fuels containing aromatic aminesand of the aromatic amines themselves.

I have found that the use of an inhibitor comprising triamyl amine, or trialkyl amine higher than triamyl amine,for example, the trihexyl, triheptyl, is most effective in preserving water white or light colored aromatic amines and fuels or other compounds containing the same from discoloration upon storage and exposure to heat and light. These inhibitors are particularly effective when used with xylidines or the commercial mixture of ortho, para and meta xylidines which form an important ingredient of many high octane motor fuels. Such commercial xylidines when freshly distilled frequently are white to a straw color, although sometimes they may be darker than that. The xylidines or fuels containing the same whether initially discolored or not when treated with the inhibitor described,

may be stored for long periods or exposed to heat and light without substantial deterioration from their original color.

The inhibiting effect of the triamyl amine or other trialkyl amine of the character described is found to be more or less proportional to the amount added. Results satisfactory for most purposes are obtained with the addition of from one-half to one percent of inhibitor to the xylidine or other aromatic amine, the color of which is to be preserved. If great permanence of color is necessary, the percentage of the inhibitor may be increased up to five percent or more. Thus, for example, a standard high octane fuel mixture containing from 2 to 4% of xylidines should have added thereto as an inhibitor a sufiicient amount of triamylamine to bring the percentage of the latter to from /2 to 1% of the xylidine content of the fuel.

Many high octane motor fuels contain lead compounds to increase their anti-knock properties. The presence of such lead compounds tends to accelerate the objectionable color changes therein. The use of the inhibiting com pound described herein is effective in controlling such color changes, although it is desirable, if a fuel is heavily leaded, to use somewhat more of the inhibitor than would be required for a non-leaded fuel. For example, with a high octane fuel containing xylidine and with about 3 cc. per gallon of commercial ethyl fluid containing lead compounds added, satisfactory permanence of color will be secured by the addition of triamyl amine to the amount of 1% to 2% of the aromatic amine content of the fuel.

I claim:

1. A high octane motor fuel containing substantial amounts of primary aromatic amines,

and as an inhibitor against color deterioration,

a small amount of a trialkyl amine selected from the group consisting of triamyl amine, trihexyl amine and triheptyl amine.

2. The process of increasing the color stability of a primary aromatic amine comprising treating it with a smallv quantity of triamyl amine.

3. An aromatic amine stabilized by the addition thereto of a small quantity of a trialkylamine selected from the group consisting of triamyl amine, trihexyl amine and triheptyl amine.

4. A color stabilized xylidine containing a small amount of triamyl amine.

5. A high octane fuel mixture containing substantial amounts of primary aromatic amines, REFERENCES CITED and as an inhibitor against color deterioration Th f llowing references are of record in the an amount of triamyl amine equal to from A; to file of this patent: 5% of the aromatic amine content of the fuel. 5 UNIT 6. A high octaine fuel mixture containing sub- ED STATES PATENTS stantial amounts of primary aromatic amines Number Name t and ethyl fluid containing lead, and as an in- 1,947,573 30nd 1934 hibitor against color deterioration an amount 2387,1393 Morrell J1me 1942 of trialkylamine selected from the group con- 10 2,306,971 McConnell 1942 sisting of triamyl amine, trihexyl amine and OTHER REFERENCES triheptyl amine equal to from to 5% of the aromatic amine content of the fuel.

'7. A primary aromatic amine containing a small quantity of triamyl amine as an agent for 15 increasing the color stability thereof.

JOHN W. ORELUP.

Chemical Abstracts (1937), vol. 31, page 2571. 

